NTRK1 and Alzheimer disease: Interestingly, the nerve growth factor (NGF) receptor TrkA accumulated to a greater extent after knockdown of hSnf7-1 than of hSnf2. In contrast, amyloid precursor protein (APP), a transmembrane protein implicated in Alzheimer's disease, and NMDA receptor 1 (NR1) accumulated more after knockdown of hSnf7-2 (Figure 6B).